(19)
(11) EP 0 376 712 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
10.04.1991 Bulletin 1991/15

(43) Date of publication A2:
04.07.1990 Bulletin 1990/27

(21) Application number: 89313634.1

(22) Date of filing: 28.12.1989
(51) International Patent Classification (IPC)5: H01K 1/32, H01K 1/34, H01K 1/50, H01K 1/54
(84) Designated Contracting States:
DE GB

(30) Priority: 28.12.1988 JP 334889/88

(71) Applicant: TOSHIBA LIGHTING & TECHNOLOGY CORPORATION
Minato-ku, Tokyo-To (JP)

(72) Inventors:
  • Watanabe, Tsutomu
    Yososuka-shi Kanagawa-ken (JP)
  • Suwa, Takumi
    Fujisawa-shi Kanagawa-ken (JP)

(74) Representative: Muir, Ian R. et al
HASELTINE LAKE & CO. Hazlitt House 28 Southampton Buildings Chancery Lane
London WC2A 1AT
London WC2A 1AT (GB)


(56) References cited: : 
   
       


    (54) Double bulb halogen lamp


    (57) In a double bulb type halogen lamp, a sealed space (49) between the inner surface of an outer bulb (13) and the outer surface of the inner bulb (15) in which a coiled filament (43) is disposed is filled with a weakly oxidising gas to avoid reduction of an optical interference film, including metal oxide substances,exposed to the sealed space.







    Search report